In the electrical utilities industry, conductor bundles can be used to transmit bulk power with reduced loss, thereby increasing transmission efficiency. A conductor bundle is a series of two, three or four conductors spaced apart by spacers to maintain spacing between each of the conductors. Bundled conductors are used on high-voltage power lines to help reduce energy losses (due to the corona effect), audible noise and radio interference. As a result, the conductor bundles improve the power transmission process.
However, one disadvantage associated with conductor bundles is that they may have conductor clashing due to subspan oscillation in high wind conditions or fault current. The spacers must maintain separation between the conductors of the bundle to minimize the effects of both subspan oscillation and fault current. Accordingly, a need exists for a spacer assembly that facilitates maintaining separation between conductors.
Elastomeric gripping members of spacer assemblies for conductor bundles are sometimes disposed between clamping bodies of the spacer assemblies and the received conductors. Elastomeric gripping elements reduces stress concentration on the conductor surface but typically result in a lower force when clamp slip occurs. However if slippage does occur, the elastomeric gripping members do not damage the surface of the conductor. Because a metal-to-metal clamp interface without the elastomeric gripping members typically has higher clamp slip, it is less likely for the metal-to-metal clamp interface to slip unless very severe forces occur on the power lines or the product was improperly installed. If slippage does occur, the metal only clamping interface can create higher stress concentration on the conductor surface, specifically at the conductor entry, thereby resulting in a higher chance for the conductor surface/outer strands to be damaged. Also, the metal-to-metal clamp interface without the elastomeric gripping members are more prone to fretting at the conductor entry/exit. After prolonged exposure to high temperatures, which can exceed 250° C., the ability of the elastomeric gripping members to substantially prevent such slippage decreases. Accordingly, a need exists for a spacer assembly for conductors in which both metal-to-metal and elastomer-to-metal clamp contact exists.
Additionally, some conventional spacer assemblies provide entirely elastomer-to-metal contact between the gripping members of the spacer assemblies and the received conductors. Accordingly, a need exists to provide a spacer assembly in which both metal-to-elastomer and metal-to-metal contact substantially prevents slippage between the spacer assembly and the received conductors after prolonged exposure to high temperatures.